Digital Cellular System
Also known as "GSM 1800", DCS is a radio frequency band used in Europe, Africa, Asia, and South America for GSM mobile phones.
DCS bands are 1710-1785 MHz and 1805-1880 MHz. There are at least five licensed sub-bands within that range in most countries that have DCS.
In the context of WCDMA and LTE networks, the DCS band is also known as band 3 (III).